Betta fish can survive for about three days without eating. Bettas are carnivorous freshwater fish. They can go without food for three days, but doing so for a long period will have adverse effects on their health and may even lead to death.
Betta fish can store a certain amount of nutrients in their bodies. When in a state of hunger, they will automatically produce substances like glycogen to meet their energy needs. However, prolonged starvation will affect various bodily functions of the betta fish, causing their physical condition to gradually deteriorate and, in severe cases, even result in death.
To keep betta fish healthy, it is recommended to feed them twice a day, and the amount of food each time should be about 1% to 2% of the size of their bellies. Feeding too much or too little will have an impact on the betta fish's body, so the amount needs to be determined according to the specific situation of the betta fish.